postgres: multiline, show transaction status in psql prompt

Author: tkareine

.psqlrc

@@ -6,5 +6,5 @@
 \set COMP_KEYWORD_CASE preserve-lower
 
 -- Reference: https://www.postgresql.org/docs/current/app-psql.html#APP-PSQL-PROMPTING
-\set PROMPT1 '%n@%m %~%R%# '
-\set PROMPT2 '%R %# '
+\set PROMPT1 '%n@%m %~ %x\n%R%# '
+\set PROMPT2 '%R%# '